Hitherto, a photographic process in which silver halides are used has been most widely used as it is excellent in photographic characteristics, such as sensitivity, gradation adjustment, resolving power, and the like, in comparison with other methods, such as electrophotography or diazo photography. The process is still being developed further, and currently it is possible to easily obtain a black-and-white image or color image with high image quality.
However, there is an increasingly strong demand for a process to obtain a photographed image more simply and rapidly, with a low environmental load. To attempt easier processing, a heat-developable color light-sensitive material for photographing containing therein a developing agent, is disclosed in JP-A-9-274295 ("JP-A" means unexamined published Japanese patent application). In heat-developing system, in general, though an image can be rapidly formed, fogging occurs readily, and attainment of good discrimination is not easy. JP-A-10-90848 discloses that, with respect to fog in a heat-developable light-sensitive material, not only emulsion fog but also development fog (heat fog) due to high-temperature processing contributes largely, and that, in order to restrain the heat fog and to achieve both high sensitivity and good discrimination of images, a specific antifogging agent is useful.
In fact that the above-mentioned antifogging agent, when used in heat-development, performs a maximum discrimination effect; however, when used in color-development process employing a currently available developing agent of paraphenylenediamine, there is a problem that it has strong desensitization effects, causing low sensitivity and/or low density. Therefore, such a light-sensitive material is unfit as a heat-developable light-sensitive material for photographing.
If a light-sensitive material for heat-development has compatibility with a conventional processing used in a widely-prevailing, small-sized, and simple printer processor, the so-called "mini-lab", installed in laboratories for color photography or stores, it can make conventional processing possible, as well as rapid processing, not requiring special additional equipment, to allow anyone to easily enjoy color photography. Such a heat-developable light-sensitive material that can be also used in conventional color-developing processing has long been desired.